<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>let 命令</title>
<script>
function Customer() {
this.nickName = '小李';
}
// 使用箭头函数定义原型对象中的方法
Customer.prototype.show = () => {
console.log(this.nickName);
}
var cust1 = new Customer();
 cust1.show(); // undefined
 </script>
 </head>
 <body></body>
 </html>